When comparing Kakoune vs Yi, the Slant community recommends Kakoune for most people. In the question“What are the best programming text editors?”Kakoune is ranked 25th while Yi is ranked 45th. The most important reason people chose Kakoune is:

It follows the UNIX philosophy by doing one thing well (text editing) and interfaces nicely with other CLI tools.

Pros

Pro

Good UNIX citizen

It follows the UNIX philosophy by doing one thing well (text editing) and interfaces nicely with other CLI tools.

Pro

Very expressive

Kakoune provides a very expressive set of commands, including various objects selection (paragraph, blocks, words), alignment support, conditional selection filtering...

This set of command is expressive enough to implement all the provided auto indentation logic.

Pro

Will be familiar to vim users

Kakoune first started as a rewrite from scratch of vim, but then ended up being another text editor altogether. So it's inspired in a lot of ways from vim.

Pro

Text selection mechanism

Kakoune works on selections, which are oriented, inclusive range of characters, selections have an anchor and a cursor character. Most commands move both of them, except when extending selection where the anchor character stays fixed and the cursor one moves around.

Pro

Actively developed and supported

Pro

More modern than vim

Pro

Combines and improves upon the best text-editing features from your favorite editors

Yi has default configurations for Vim, Emacs, as well as CUA. It also makes several improvements that includes Sublime-like (multiple) cursors.

Pro

More performant than Vim

Vim can be rather slow due the age of its code base. In particular, running large macros in Vim can be rather painful. Since Yi is being built from scratch it has been engineered for performance and with the benefit of hindsight.

Pro

Extensible and modular editing features

As far as extensibility goes, Yi easily outstrips any other open-source text editor. Motions can be built from parser combinators, making them simultaneously flexible and modular - an open source hacker's dream.

Pro

Plugins work together

Packages work together because they compile together.

Cons

Con

Small community

Con

Very few plugins available

Even though Yi is a general purpose text editor similar to Vim and Emacs, almost all of the plugins that have been written for Yi so far focus on supporting Haskell as a programming environment.

Con

No way to reuse your existing customizations and keybindings

If you have spent years crafting your .vimrc or .emacs, there's no way to reuse it in Yi. You have to start from scratch.

Con

Requires Haskell to compile and configure

GHC + Haskell packages makes for a rather large installation, which is a big ask for a relatively obscure terminal editor.